Gas-liquid mixing apparatus



E. H. EPPRECHT 2,928,665

GAS-LIQUID MIXING APPARATUS Original Filed Sept. 27, 1950 March 15, 19604 Sheets-Sheet l F I E 1. INVENTOR.

/fi/um flTToRNEY- March 15, 1960 E. H. EPPRECHT 2,928,665

GAS-LIQUID MIXING APPARATUS Original Filed Sept. 27, 1950 m 4Sheets-Sheet 2 IN VEN TOR.

A-r TORNEY March 15, 1960 E. H. EPPRECHT GAS-LIQUID MIXING APPARATUSOriginal Filed Sept. 27, 1950 4 Sheets-Sheet 3 IN V EN TOR.

March 15, 1960 E. H. EPPRECHT GAS-LIQUID MIXING APPARATUS Original FiledSept. 27, 1950 4 Sheets-Sheet 4 R. W2 Y t N A m y n B 61 u w ,m I A 1/IF GAS-LIQUlD MDflNG APPARATUS-s Edward H. Epprecht, Takoma ParkLMdLassignor to American Instrument Ciimpany;,lrie;, SilverSpring,"

8 Claims." (Cll 2161- 87)" This is a division of my. previously filedapplication; Serial No. 187,037, filed Sept. 27, 1950;"; and' entitledGas-Liquid Mixing Apparatusfissued;as*U;S Patenti This inventionrelateslto. mixing'apparatus; and more particularly to improvedapparatusffor mixing 'gaseswith liquids.

A main object of the invention'isto provide a novel and improved mixingapparatus whichiis'simplein com struction, which is efficient'inoperation, and whichprm vides homogeneous distribution ,of 'a gasthrough a-liquid with which it is to be mixed,

A further object of the invention is: to provide an improved mixingapparatus for mixing aagas with'a liquid, saidapparatus involvingrelatively inexpensiveparts; being very durable in construction,and;providing'fthorough distribution of gas-in a liquid with amaxifirumainount of agitation andmechanicaljdisturbanceiof the liquid.

A still further object of the invention is"to"provide an improved mixingapparatus for-mixing .a gas with a liquid,

said apparatus employing an improved and' novel ar-' rangement ofsuction-producing means whereby 'th'e gas' .is aspirated into the liquidcontinuously during'the operation of the. apparatus, the suctionrequiredforaspiration being produced by movingportions QfJthe'apparatusFigure 2 is an enlarged crosses'ectional view taken on line 2--2 ofFigure l. I

Figure 3 is a fragmentary vertical cross-sectionalview ttes Patentthebore 13 by means of bolts 21 which extend through a flangeonthe gland:member. 19' and are threadeda intothe boss portion 16, as shown. Theshaft 17 is -therebysealingly and rotatablyengaged in the member 13.

As shown in Figure 1, the shaft member:1 7' is :formed with an axialbore 22.. Secured to the lower end-of the shaft member 17 is thedome-like member 23 wh'ose interior communicates witlr the bore 22, asshown in Figure 1.

' openings 24 which provide communication b'et'ween...the-

taken through the lower portion of; astill'further'modi fied form ofmixing. rotor accordingt'o the present in vention, said viewbeingtta'ken on.- line 3-3 of Figure 42 Figure 4 is across-sectionaliview taken on. line 4-4 of Figure 3. a

Figure 5 is a fragmentary bottom plan view of" the modified form ofmixing rotor of Figures 3 and4.

Figure 6 is a fragmentary vertical cross-sectional view taken throughthe lower portion ofa still'further modified form of mixing rotoraccording to the present invention, said view being taken on line. 6.-6of Figure];

Figure 7 is a horizontal cross-sectionalview'taken on line 77 of Figure6.

Figure 8 is afragmentary bottom plan view of" the modified form ofmixing rotor. shownin Figuress6'and7.

Referring to the drawings, and more particularly to,

space external to theshaft17'and'the interior of the bore 22. Designatedat 25-is a cylindrical sleeve which is disposed around the shaft 17and'is coaxial therewith,- said sleeve being secured to an-annulardrum-shaped" member 26-which is bolted to theboss member 16, as by thebolts 27. The upper portion of the sleeve member- 25 is formed withapertures 28'which establish communicationbetween the interior of thesleeve'member 'and the space'in the upper portion of thevessel 12;

Designated at29 is= an annular disc member-whieh is secured to therimportion of the dome-like. memb'en23 bya plurality of spacedbolts 30,said bolts being= arranged' at equal angular distances around the axisof the shaftmember 17. The annular disc member 29' hasse cured thereto aplurality of evenly spaced'radialvertieal wall elements 31,definingradial'passages. Designated.

at 32is a circular disc'which is interposed between the top radial edgesof the wall members 3-1 and the annular surface of arecessed-seat 33formed-in the bottom rim ofthe dome-like member 23. a

As shown in Figures 1 and 2, the disc 32 is formed with respectiveapertures 34,- each aperture being located adjacent the intermediateportion of arespective passage defined between an adjacent pair of wallmembers 31. As will be further seen from Figure l, the annular disc 29is substantially flaton its bottom surfacebut is formed with a topsurface which is bevelledboth inwardly'and outwardly from itsintermediate portionto define a generally venturi-shaped cross-sectionwith respect to the disc 32, the aperture 34 associated with'eachabove-mentioned' radial" passage being located adjacent the constrictedintermediate portion of the passage.-

In operation, the liquid and gas-to be mixed are-first introducedcintothe vessel 12 in anysuitable manner; and the body 13 issealingly'secured to the top rim ofvessel 12, as by-the bolts 14;The-shaft 17 is connected to a suitable driving means, for example,the'output shaftofa slow-speed-motor. As the rotor defined by the shaft17 and the elements secured thereto revolves, liquid flows in: wardlythrough the central opening of the annular disc member 29 and enters theradial passages defined between the radial wall elements 31. The liquidflowsoutwardly through said radial passages by centrifugal force, and asthe liquid passes through the venturi-like portions ofsaid radialpassages, reduction in pressure is developed adjacent the constrictedpassage portions as the liquid is moved radially outwardly therethrough.This reduction in pressure providesa substantial degree of'suctionwhich,

causes gas from'the upper portion of the vessel 12- to be aspirated intothe liquid as said'liquid is moved outwardly through the passages. Thegas in the upper portion of thevessel flows through the openings 28 andthrough'the apertures 24 into the bore 22, and then flows downwardlyPatented Mar. 15, 1960 The shaft member '17 is formed adjacent-the:-upper end portion of the bore 22 with a'plura-lityof through said boreinto the space defined within the domelike member 23. The gas then flowsthrough the respective apertures 34 into the aspirator passages, whereinthe gas ismixedr'into' the'liquid as'theliquid flows outwardlythroughrsaid passages. It. will be readily apparent that the rotarymotion of theshaft causes liquid to. 'move outwardly from the bottomportion of the rotor through said passages by centrifugal force, theflow of the liquid through the above-mentioned aspirator passages,providing the necessary reduction in pressure to .produce the aspiratingaction.

In order to increase turbulence and. mechanical agitation oftheliquid, aplurality of radial bafiie plates 35 are secured to the lower endportion of thesleevemember 25, said baffle plates serving: to preventthe formation of a vortex around the sleeve member asthe' shaft 17rotates.

As will'be evident from Figure l, theliquid which is to be treated,designated at 36, is disposed in'the vessel 12 to a depth sufiicient tocover the lowerportion of the rotor and the lower portion of the sleeve25,'whereby-the dome-like member 23 and the. elements carried therebyare completely immersed in the liquid. The gas which is to'be mixed withthe liquid fills the upper portionrof the vessel 12 and is freelyaccessible to the interior of the bore 22 through the openings28 and24., As the gas is distributedlthrough the liquid the level of themixture rises until finally a completely homogenous mixture of gas andliquid is produced.

Referring now to Figures 3, 4 and 5, a further modification ofa rotoraccording to the present invention, is disclosed. Secured to the end ofthe shaft 17 is a dome-like member 123', and secured to the rim of saiddomerlike member in opposing relation thereto is the circulardishedmember .50, the opposing surfaces of the members 123 and 50beingseparated by suitable washers 51 encircling the fastening bolts,shown at 52. As shown in Figure -3, the rim portions of the members123". and 50 are-tapered so as to define outwardly flaring annularspaces 53 b :1,

tween, said rim portions. Designated at 54-and 55 are respective annularfiat ring elements whichare disposed tures.

a '4 a increased in area, whereby a reduction in pressure is producedadjacent the flaring space 53 at the gas escape aper- This reduction inpressure produces aspiration of the gas into the liquid as the liquidflows outwardly between the members 54 and 55-by centrifugal forceresponing with the liquid. Liquid moving outwardly by cen- V trifugalaction past said expansion space through the radial passages definedbythe radial partition members 60and 63 produces an aspirating action,causing a reduction in velocity of the gas discharging from saidexpansion space, whereby .thei high-velocity, low-pressure gas is mixedwith the outwardly moving liquid in said radial passages.

Referring now to l igurestfi, and 8 ,lan" arrangement generally similarto that disclosed in Figures 3 ,to 5 is illustrated except that the legportions of the wall members, shown respectively. at'62',and 59,, aresubstantially longer than in the form .of the invention of Figures 3 to5,

the lower legpo'rtions 62 extending inwardly to positions wherein theysubstantially contact each other, as shown in Figure 8. However,theloperation of the rotor of Figures 6, 7 and 8 issubstantiallysimilartothat of the rotor of Figures 3, 4 and 5 in that liquid flows into therotor through the inlet openings and .65 and'flows throughthe relativelyconstricted passages defined between the opposing surfaces of members 54and 123 and members 55 and 50, and thence emerges into the passageportions of greatly increased icross sectional area outward- 1yadjacentthe flaring space53 between the peripheral portions of themembers 123? and 50. The outward movement of the liquid by centrifugaliforcethrough said relativelyconstrictedfpassage portionsprovides thereducrespectively above and below the dome-like member123' and thedished member in the manner shown in Figure 3. The member 54 is formedwith a peripheral flange 56 and the member is similarly formed with aperipheral flange 57. The upper surface of the member 123=is formed withrespective pairs of radial lugs 58 which receive therebetween the radialleg portions 59 of generally L-shaped radial partition elements 60. Theouter portions of the elements, 60 depend adjacent the peripheral edgesof the members 123 and 50, and define radialpartitions beyond theperipheries of members 123 and 50. Similarly, the bottomsurface of themember 50 is formed with respective pairs of radial-lugs 61 whichreceive the leg'portions' 62 of generally L-shaped wall elements 63, theouter portions of said wall elements 63 rising vertically adjacent theperipheral edges of the mem-' bers 123 and 50, and defining radialpartitions similar to the partitions 60. The partitions thus defined bythe the washers 51, thereby defining passages through which gas may.emerge from the hollow shaft 17 into the liquidi The clamping Thecentral apertures 64 and 65 of the members5 4and 55 define-inletpassages for the liquid, and the-respective leg elements 59 and 62define radial passages wherebythe liquid may fiow into the space betweenthe annular members 54 and 55 past the peripheral portions of thememhers 123' and 50. As the liquid flows past said peripheral L Pe the Ps e a e: l quid Presets ssbsfiatia i tion in .p'ressure' adjacent thegas, outlet space 52 which "produces aspiratingactionof the gasinto theliquid as the liquid moves into the outer-portion of the. rotor.

While certain specific embodiments of apparatusfor mixing gas withliquid have been disclosed in the foregoing description, it will beunderstood that various additional modifications within the spirit ofthe invention may occur to those skilled in the art. Therefore it isintended that .no limitations beplaced on the invention except asdefined by the scope of theappended claims.

What is claimed is: h p

1. mm apparatus .formixing jgas and liquid, arotor comprising ahollowshaft, a first dome-like member axially. securedto theje'nd ofsaid shaft and communicat ing with the bore thereof, a seconddome-like,,memher secured, tothe first dome-like member in opposingrelai tion thereto, spacer means interposed between the periph:

eralmargins .of, the domedilce, members and defining a substantiallyannular constricted passage therebetween, the rim portions or thedome-like members being formed to define an outwardly flaring annularexpansion space therebetwe'en communicating directly with said annularconstricted passage, an annular plate member secured in spacedrelationto, thedome-like members coaxially therewith, and'fa pluralityofradial wall 'elementssecured between the dome-like members andtheannular plate member and.having-inneredges located adjacent andradially outward of said flaring'expansionspace, saidradial wallelements being constructedand arranged todefine radial passages.adjacentpto and extending past the peripheral "marginal portions of thedome-like. members, said radial passages increasing outwardly in areaand extending outwardlygpasfsaid, annular expansionspace, whereby gas kfl sin' 'ioutwardlytt om be we n t a i hersihroughfsaid, constrictedpassage is reduced in veloc i ty as .itldischargesfinto saidannularexpansionspace, and

whereby liquid'qmoying outwardly past the expansion piighisaidradialpassages by centrifugal act on said radial passages.

2. In an apparatus for mixing gas and liquid, a rotor comprising ahollow shaft, a first dome-like member axially secured to the end ofsaid shaft and communicating with the bore thereof, a second dome-likemember secured to the first dome-like member in opposing relationthereto, spacer means interposed between the peripheral margins of thedome-like members and defining a substantially annular constrictedpassage therebetween, the rim portions of the dome-like members beingtapered outwardly in thickness so as to define an outwardly flaringannular expansion space therebetween communicating directly with saidannular constricted passage, a pair of annular plate members secured onopposite sides of and in spaced relation to the dome-like memberscoaxially therewith, and a plurality of radial wall elements securedbetween the annular plate members and having inner edges locatedadjacent and radially outward of said outwardly flaring expansion space,said wall elements being constructed and arranged to define radialpassages adjacent to and extending on opposite sides of the peripheralmarginal portions of the dome-like members, said radial passagesincreasing outwardly in area and extending past said outwardly flaringexpansion space, whereby gas discharging outwardly from between thedome-like members through said constricted passage is reduced invelocity as it discharges into said annular expansion space, and wherebyliquid moving outwardly past the expansion space through said radialpassages by centrifugal action produces an aspirating action, causing areduction in pressure and increase in velocityof the gas dischargingfrom said expansion space, and whereby the high-velocity, lowpressuregas is mixed with the outwardly moving liquid in said radial passages.

3. The structure of claim 2, and inwardly directed leg portions on saidradial wall elements disposed between said annular plate members andsaid dome-like members.

4. The structure of claim 2, and wherein said radial wall elementscomprise generally L-shaped members having inwardly directed legportions disposed between said annular plate members and saiddome-likemembers.

5. The structure of claim 2, and wherein said radial wall elementscomprise generally L-shaped members having inwardly directed legportions disposed alternately in the space between the first dome-likemember and the annular plate member adjacent thereto and in the spacebetween the second dome-like member and the annular plate memberadjacent thereto.

6. The structure of claim 2, and wherein said radial wall elementscomprise generally L-shaped members having inwardly directed legportions, some of said leg portions being disposed in the space betweenthe first domelike member and the annular plate member adjacent vthereto and other of the leg portions being disposed in the spacebetween the second dome-like member and the annular plate memberadjacent thereto.

7. The structure of claim 6, and wherein said other of the inwardlydirected leg portions are of suflicient length to substantially meetadjacent the axis of the shaft;

8. The structure of claim 2, and wherein said spacer means comprises aplurality of spaced washers secured between the rim portions of thedome-like members.

References Cited in the file of this patent UNITED STATES PATENTS1,040,664 Griffith et al. Oct. 8, 1912 1,242,445 Ittner Oct. 9, 19171,345,596 Hovland July 6, 1920 1,583,591 Greenawalt May 4, 19261,726,125 Rowand Aug. 27, 1929 1,726,136 Antisell Aug. 27, 19291,768,955 Johnson July 1, 1930 1,768,957 Johnson' July 1, 1930 1,771,321,Snow July 22, 1930 1,779,181 McDonald Oct; 21, 1930 2,104,349 MacCamyJan. 4, 1938 2 ,343,274 Bailey et al. Mar. 7, 2,448,590 Gunther Sept. 7,1948 2,609,189 Dering Sept. 2, 1952 2,743,914 Epprecht May 1, 1956FOREIGN PATENTS 218,637 Switzerland Apr. 16, 1942 a 466,143

Great Britain May 24, 1937

